Cranial cerebrospinal fluid leak and intracranial hypotension syndrome - a case report

Abstract

Spontaneous intracranial hypotension is a rare clinical entity caused in most cases by a cerebrospinal fluid leak occurring at the level of the spinal cord. Cranial dural leaks have been previously reported as a cause of orthostatic headaches but, as opposed to spinal dural leaks, were not associated with other findings characteristic of spontaneous intracranial hypotension. We present the case of a male admitted for severe orthostatic headache. The patient had a history of intermittent postural headaches, dizziness, and symptoms consistent with post-nasal drip, which appeared several years after head trauma. Brain imaging showed signs consistent with intracranial hypotension: bilateral hygromas, subarachnoid hemorrhage, superficial siderosis, diffuse contrast enhancement of the pachymeninges, and superior sagittal sinus engorgement. No spinal leak could be identified by magnetic resonance imaging, and the patient had a rapid remission of symptoms with conservative management. Further work-up identified an old temporal bone fracture which created a route of egress between the posterior fossa and the mastoid cells. Otorhinolaryngology examination showed pulsatile bloody discharge and liquorrhea at the level of the left pharyngeal opening of the Eustachian tube. The orthostatic character of the headache, as well as the brain imaging findings, were consistent with intracranial hypotension syndrome caused by a cranial dural leak. Clinical signs and imaging findings consistent with the diagnosis of apparently "spontaneous" intracranial hypotension should prompt the search for a cranial dural leak if a spinal leak is not identified.

Keywords: CSF – cerebrospinal fluid; CT – computed tomography; ENT – otorhinolaryngology; MRI – magnetic resonance imaging; SIH – spontaneous intracranial hypotension; cranial dural leak; intracranial hypotension; orthostatic headache; temporal bone fracture.

Figure 1.

Axial native CT scan showing subarachnoid hemorrhage located in the frontal lobes bilaterally and in the left temporal lobe (A); Follow-up CT scan performed 48h later showing bilateral hygromas (B); Coronal FLAIR showing superior sagittal sinus engorgement, dilated cortical veins, hemorrhage in the left temporal lobe (C); Sagittal T1-weighted imaging showing sunken splenius (D); Axial SWI showing superficial siderosis (E); Axial T2-weighted imaging showing hygromas and hemorrhage in the right frontal lobe (F).

Figure 2.

Sagittal hr-CT reconstruction of the temporal bone showing bone fracture involving the mastoid cells (A) and (B); Sagittal T2- weighted MRI showing hyperintense signal in the left mastoid cells (C); hr-CT scan reconstruction in coronal and axial planes showing the fracture involving an antral cell (D) and partial opacification of the left mastoid cells (E).